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Results 451 - 500 of 1138
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Berndtson A K - - 1989
The present study investigated the effects of 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17,20 B-P) on (1) ovulation of isolated perch follicles in which the extrafollicular (EF) ovarian tissue had been removed; (2) prostaglandin F (PGF) and prostaglandin E (PGE) synthesis in EF tissue and intact (= follicles attached to EF tissue) and ...
Hughes P - - 1989
The synthesis of 4,6-diethyl-1,3,4,5-tetrahydropyrano[4,3-b]indole-4-acetic acid, an isomer of the antiinflammatory agent etodolac, is described. The compound was found to have an ED50 of 3 mg/kg po in the rat curative adjuvant arthritis assay, and an IC50 of 50 nM for inhibiting prostaglandin production in cultured chondrocytes.
Hafez M M - - 1989
The effect of prolactin on phospholipid metabolism in the prolactin-dependent rat lymphoma cell line Nb2 was investigated in cells prelabeled with [3H]arachidonic acid or [3H]ethanolamine. Prolactin (20 ng/ml) caused (a) a 20-60% loss of radiolabeled phosphatidylethanolamine within 0.5 to 2 min, (b) a loss of [3H]ethanolamine-labeled phosphatidylethanolamine from crude membranes, ...
Kaminski D L - - 1989
Arachidonic acid metabolites are involved in a wide spectrum of hepatobiliary physiologic functions and disease. Prostanoids alter hepatic bile flow. Prostaglandins with a C9 ketooxygen stimulate a bicarbonate-rich choleresis and those with a C9 hydroxyloxygen produce a chloride-rich choleresis. Prostaglandin F2 alpha stimulates the release of the potent choleretic glucagon ...
Medow M S - - 1989
Previous studies have shown that treatment of cultured rabbit coronary microvessel endothelial (RCME) cells with dexamethasone results in a dose-, time-, and glucocorticoid-dependent inhibition of prostaglandin release. In the present study, the effects of dexamethasone on RCME membrane lipid composition and release of arachidonic acid were examined. This study demonstrated ...
Freyberger A - - 1989
Prostaglandin-H-synthase (PHS) is a key enzyme in the biosynthesis of prostaglandins (PGs) from arachidonic acid and can oxidatively metabolize synthetic and steroidal estrogens. To investigate the relationship between estrogen cooxidation and PG synthesis, purified PHS-holoenzyme was incubated with radiolabeled arachidonic acid and various estrogens, namely diethylstilbestrol (DES), estradiol (E2), 2-hydroxyestradiol ...
Santoli D - - 1989
Essential fatty acids, from which PG derive, can participate in development and regulation of immune responses and have been shown to suppress inflammation and tissue injury in animal models. In this report, we investigate the effects of the immediate (DGLA, precursor to PGE1), arachidonic acid (AA, PGE precursors, dihomogamma linolenic ...
Kusunose E - - 1989
Two different forms of cytochrome P-450, highly active in the omega-hydroxylation of prostaglandin A, and the omega- and (omega-1)-hydroxylation of fatty acids (P-450ka-1 and P-450ka-2), have been purified from kidney cortex microsomes of rabbits treated with di(2-ethylhexyl)-phthalate. On the basis of the peptide map patterns and NH2-terminal amino acid sequence, ...
MacDonald I D - - 1989
A combination of cyclooxygenase activity assays, rapid spectrophotometry and pre-steady-state, steady-state, and transient-state kinetics is used to characterize further the properties of prostaglandin H synthase. 13-Hydroperoxyoctadeca-9-11-dienoic acid is used as oxidizing substrate and the effects of the following compounds are examined: arachidonic acid, N,N,N',N'-tetramethyl-p-phenylenediamine, phenol, diethyldithiocarbamate, and the nonsteroidal anti-inflammatory ...
Gray P R - - 1989
Airway obstruction and hyperreactivity are characteristics of human asthma and of "heaves," a naturally occurring respiratory disorder of horses and ponies. To document the role of cyclooxygenase products of arachidonic acid metabolism in the pathogenesis of heaves, we measured plasma and bronchoalveolar lavage (BAL) fluid concentrations of metabolites of thromboxane ...
Waymack J P - - 1989
Elevations in prostaglandin E (PGE) have been documented in tumor and trauma patients. The physiologic significance of this elevation is not fully established. Utilizing a long-acting derivative of PGE, 16,16-dimethyl-prostaglandin E (dPGE), in a rat model, we evaluated its effects on metabolic rates, amino acid, and neurotransmitter metabolism. dPGE was ...
Rosing U - - 1989
Fractionated curettage was performed in 18 women with cervical intraepithelial neoplasia. Otherwise all appeared to be healthy. The histological examination showed 9 of them to have been sampled in the follicular phase and the other 9 in the luteal phase. Endometrial specimens were simultaneously taken for analysis of the fatty ...
Yang C Y - - 1989
Prostaglandins (PGs) are a group of 20-carbon unsaturated fatty acids derived from arachidonic acid, one of the key components of phospholipids in animal cell membranes. Although PGs were originally named and discovered in the prostate gland of man and sheep, current evidence suggests that PGs are synthesized by nearly all ...
Van der Zee J - - 1989
Quin2 and its analogs BAPTA, 5,5'-dimethyl BAPTA, 5,5'-difluoro BAPTA, fura-2, and indo-1 were developed to measure intracellular calcium concentrations. In this study we investigated whether quin2 and its analogs are susceptible to peroxidase-catalyzed oxidation. The hydroperoxidase activity of prostaglandin H synthase, like other peroxidases, is capable of oxidizing a wide ...
Dieter P - - 1989
Incubation of liver macrophages with zymosan, phorbol ester and calcium ionophore A 23187 led to the formation of thromboxane, prostaglandin E2 and prostaglandin D2, whereas after external addition of arachidonic acid prostaglandin E2 and prostaglandin D2 only were found. This was confirmed by the use of labeled arachidonic acid given ...
Allgayer H - - 1989
Colitis was induced in rats by intrarectal administration of trinitrobenzene sulfonic acid (80 mg/kg, in 30% ethanol). An acute inflammation with ulcers and neutrophil infiltration developed that evolved into a chronic inflammation and luminal narrowing with attendant smooth muscle hypertrophy. We assessed the effects of 16,16-dimethyl prostaglandin E2, administered either ...
Duniec Z M - - 1989
The objectives of our investigations were to characterize the profile of arachidonic acid metabolites produced by cultured rat tracheal epithelial cells, and to determine whether or not transformation of these cells causes major qualitative or quantitative changes in arachidonic acid metabolism and whether arachidonic acid metabolites play an important role ...
Iyer R S - - 1989
Levuglandin E2 (LGE2), a gamma-ketoaldehyde produced by rearrangement of the prostaglandin endoperoxide PGH2 under the aqueous conditions of its biosynthesis, causes extensive intermolecular crosslinking of ovalbumin at pH 6 or pH 7 and 37 degrees C. The time dependence of protein oligomerization is monitored by SDS-PAGE. Effects of pH and ...
Hamazaki T - - 1989
Epidemiological studies were performed in a Japanese fishing village when catches of fish were highest and in a Japanese farming village with usual fish consumption. Intake of eicosapentaenoic, docosahexaenoic and also arachidonic acid were significantly higher in the fishing village during the 3 days of the study than in the ...
Chansel D - - 1989
Modulation of renin synthesis by lipoxygenase products has been studied in cultured human mesangial cells under basal conditions and in the presence of prostaglandin (PG) E2. Total renin and cyclic AMP productions were stimulated in a dose-dependent manner (0.1-10 microM) by PGE2. The stimulatory effect of PGE2 on renin production ...
Das U N - - 1989
Micronutrients, vitamins A, C, and E, beta-carotene, and selenium can decrease the incidence of cancer, possibly due to their antioxidant action(s). These nutrients prevent lipid peroxidation, especially that of gamma-linolenic, dihomo-gamma-linolenic and arachidonic acids, the precursors of prostaglandins. Gammma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA), prostaglandin E1 (PGE1) and prostacyclin can ...
Klein A - - 1989
We have shown previously that cortisol-sensitive lymphocytes (thymocytes) have a much lower capacity than cortisol-resistant cells to catabolize cortisol and that linoleic acid inhibits the catabolism of cortisol by lymphocytes and modulates the sensitivity of lymphocytes to cortisol. In the present study, we attempted to see whether other fatty acids ...
Prusch R D - - 1989
Phagocytosis in Amoeba proteus can be induced with prostaglandins (PG). In addition, arachidonic acid (the fatty acid precursor to the PG-2 series) also induces phagocytosis. The induction of phagocytosis with arachidonic acid can be partially inhibited by the cyclooxygenase inhibitor indomethacin. Phagocytosis in the amoeba can also be induced with ...
Basu S - - 1989
Arachidonic acid is metabolised via the cyclo-oxygenase pathway to several biologically active metabolites. These metabolites control important reproductive functions like luteolysis of the corpus luteum. The metabolism of arachidonic acid was studied by the enzymatic conversion of [1-14C]-labelled arachidonic acid in sheep endometrial tissue. The inhibitory capacity of sheep endometrial ...
Brass E P - - 1989
The hepatic level of prostaglandins will reflect the balance between synthesis of prostaglandins and their rapid catabolism via beta-oxidation by hepatocytes. In the present study we examined the effect of physiological fuel substrates on the breakdown and action of prostaglandin E2 (PGE2) in isolated rat hepatocytes. Palmitic acid (0.32 mM), ...
Fogh K - - 1989
The biochemical events leading to atopic dermatitis (AD) are unknown. Certain eicosanoids derived from arachidonic acid are potent mediators of skin inflammation and modulators of certain T-lymphocyte activities. The purpose of the present study was to determine whether eicosanoids are present in biologically active concentrations in the skin of adult ...
Burgess J R - - 1989
The human glutathione S-transferases 1-1 and 2-2, which differ from each other by 11 amino acids, have different catalytic activities against cumene hydroperoxide and t-butyl hydroperoxide. Using prostaglandin H2 as the peroxide substrate, we found that GSH S-transferase 1-1 catalyzed the transformation of prostaglandin H2 to prostaglandin F2 alpha and ...
Muerhoff A S - - 1989
Terminal acetylenic fatty acid mechanism-based inhibitors (Ortiz de Montellano, P. R., and Reich, N. O. (1984) J. Biol. Chem. 259, 4136-4141) were used as probes in determining the substrate specificity of rabbit lung cytochrome P-450 isozymes of pregnant animals in both microsomes and reconstituted systems. Lung microsomal and reconstituted P-450 ...
López Bernal A - - 1989
Discs of amnion and choriodecidua prepared from women delivered at term were incubated with and without surfactant prepared from human amniotic fluid and the output of prostaglandin E (PGE) was estimated by radioimmunoassay. Surfactant stimulated the release of PGE in both tissues. The stimulatory effect was characterized further using cultured ...
Tahara K - - 1989
The present study and the previous report (6) show that the cyclooxygenase path is a primary route of metabolism of arachidonic acid in FRTL-5 rat thyroid cells. The production of PGD2 and PGE2 is an active process in intact cells treated with complete medium including TSH, insulin and 5% calf ...
Stiegler H - - 1989
The influence of intra-arterial (i.a.) prostaglandin E1 (PGE1) on the metabolism of amino acids, glucose and free fatty acids in healthy volunteers was determined by means of the forearm technique. The continuous increase of perfusion from baseline 2.9 +/- 0.1 ml/100 g x min to 5.4 +/- 1.5 after 60 ...
Yavin E - - 1989
Hypoxic-ischemic insults caused by placental insufficiency in perinatal life are today considered a major cause for neuronal injury and impaired postnatal development. A major consequence of placental insufficiency and ischemia is the change in metabolism of arachidonic acid and its oxidation products. A burst of postischemic production of prostaglandins, unequivocally ...
van Kammen D P - - 1989
Psychotic disorders, particularly schizophrenia, are associated with clinical phenomena that can be explained by disturbances in polyunsaturated fatty acid and prostaglandin metabolism. Previous studies of PUFA, PG synthesis, PGE1 receptor activity and aggregation responses in platelets, and clinical treatment trials suggest a role for PGE in the pathophysiology of schizophrenia. ...
Park J H - - 1989
We have shown that dietary long-chain triglycerides and 16,16-dimethyl prostaglandin E2 enhance and aspirin impairs postresection mucosal adaptation in rats. The present studies examined the hypothesis that supplemental linoleic acid (LA) above the minimum requirement may enhance postresection mucosal adaptation through altered prostaglandin (PG) synthesis. Forty male Sprague-Dawley rats (105 ...
Matsumoto H - - 1989
1. Prostaglandin (PG) syntheses from labelled highly unsaturated fatty acids were investigated in washed thrombocyte suspensions of four species of marine fish, flounder (Paralichthys olivaceus), black seabream (Acanthopagrus schlegeli), black rockfish (Sebastes schlegeli), and red seabream (Pagrus major). 2. Synthesized PGs were analyzed by thin-layer radiochromatogram scanner and high-performance liquid ...
Penston J G - - 1989
This review summarizes the effects of prostaglandins on gastric emptying in animals and man. It appears that prostaglandin E2 (PGE2) and prostaglandin F2 alpha increase the rate of gastric emptying in animals. PGE2 increases the emptying of liquids from the human stomach; more recently developed prostaglandin analogues, however, such as ...
Fischer S - - 1988
Prostaglandins E3 and F3 alpha, presumably of renal origin, were characterized for the first time in urine of volunteers after ingestion of n - 3 polyunsaturated fatty acids by combined gas chromatography-mass spectrometry. Quantitation of prostaglandins E3, E2, F3 alpha and F2 alpha using deuterated internal standards showed low levels ...
Chock S P - - 1988
The identification of a non-bilayer phospholipid storage in the secretory granule and the linking of the eicosanoid production with the release of histamine have prompted us to examine whether the secretory granule may also serve as both the source as well as the site of prostaglandin synthesis during exocytosis. By ...
Berkenkopf J W - - 1988
The magnitude and temporal production of PGI2, PGE2 and LTB4 were measured in the mouse peritoneal cavity for a 15 min period following the intraperitoneal injection of either acetic acid, phenyl-p-benzoquinone (PBQ) or zymosan. For each algogenic substance, PGI2 (assayed as the stable metabolite, 6-keto-PGF1 alpha) represented the major eicosanoid ...
Gardiner N S - - 1988
Both ascorbic acid and the 1-series prostaglandins have been reported to be important regulators of cell growth and since ascorbic acid also increases the synthesis of the 1-series prostaglandins, it is possible that the effects of ascorbic acid on cell growth might be mediated by changes in 1-series prostaglandin synthesis ...
Tarayre J P - - 1988
Thanks to local application of various compounds that inhibit the effects or the synthesis of histamine, serotonin, prostaglandins, thromboxanes and leukotrienes, hypotheses are proposed about the possible role of these mediators in various experimental inflammations induced on mouse ear: reactions to arachidonic acid, croton oil and cantharidin (6-h and 24-h ...
Marshall P J - - 1988
Prostaglandin H synthase has two distinct catalytic activities: a cyclooxygenase activity that forms prostaglandin G2 from arachidonic acid; and a peroxidase activity that reduces prostaglandin G2 to prostaglandin H2. Lipid hydroperoxides, such as prostaglandin G2, also initiate the cyclooxygenase reaction, probably via peroxidase reaction cycle enzyme intermediates. The relation between ...
López Bernal A - - 1988
Discs of human amnion prepared from nine women delivered by elective caesarean section at term were incubated with and without purified human amniotic fluid surfactant (9 micrograms lipid P/ml), and the output of prostaglandin E (PGE) was estimated by radioimmunoassay. Surfactant stimulated the release of PGE from 3.8 (SD 2.9) ...
Stein B E - - 1988
Eicosanoids modulate the response of gastrointestinal mucosa to noxious stimuli. Though these compounds have been extensively investigated in the stomach, their role in the esophagus has received less attention. Thus, the metabolism of 14C-arachidonic acid by homogenates of rabbit esophageal mucosa was investigated. The major metabolites formed and separated by ...
Nassar B A - - 1988
We investigated the effects of phenelzine and tranylcypromine on the release of prostacyclin, thromboxane A2, prostaglandin E2, and prostaglandin E1 from the isolated perfused rat mesenteric vascular bed. Perfusion of the preparation with phenelzine in concentrations of 15, 45, and 135 microM for 150 min led to attenuated release of ...
Redfern J S - - 1988
Antral and fundic mucosal homogenates obtained from prostaglandin E2-immunized rabbits converted 14C-arachidonic acid to prostaglandin E2, 6-keto prostaglandin F1 alpha, prostaglandin F2 alpha, and prostaglandin D2. Percentage conversion of 14C-arachidonic acid to these prostaglandin products was not significantly different in prostaglandin E2-immunized rabbits compared with control rabbits (thyroglobulin-immunized and unimmunized ...
Taiwo Y O - - 1988
It has been suggested that bradykinin (BK) and norepinephrine (NE) induce hyperalgesia, indirectly, by stimulating the production of prostaglandin products of the cyclo-oxygenase pathway of arachidonic acid metabolism. However, the specific PGs that mediate the hyperalgesic effects of BK and NE are unknown. Two endogenous PGs, prostaglandin E2 (PGE2) and ...
Martin H A - - 1988
1. We have recently shown that leukotriene B4 (LTB4), a product of the 5-lipoxygenase pathway of arachidonic acid metabolism, sensitizes nociceptors to mechanical stimuli. The present study examined whether LTB4 also induces a heat sensitization of cutaneous C-fiber nociceptors. The C-fiber nociceptors studied had von Frey hair thresholds greater than ...
Parker J - - 1988
The mechanism of tumor promotion may involve stimulation of prostaglandin production. Previous studies with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) have identified two effects of TPA on prostaglandin production. TPA stimulates both arachidonic acid release and de novo synthesis of prostaglandin H synthase. Activation of protein kinase C by TPA appears ...
Rice G E - - 1988
The capacity of cotyledonary microsomes, prepared from pregnant ewes (20-145 days of gestation), to metabolize exogenous arachidonic acid was quantified using a radiolabel technique. During gestation, the capacity of microsomes to metabolize arachidonic acid increased 25-fold, from 0.36 +/- 0.06 mumol arachidonic acid/incubation (n = 8) at less than 100 ...
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